Viral hepatitis can be divided into seven types of A, B, C, D, E, F and G Hepatitis C is the most common one and is a kind of infectious disease targeting liver organs caused by hepatitis C virus (hepatitis C virus, HCV). About 3 percent of the global population has been infected with the hepatitis C virus.
Hepatitis C virus (HCV) is a positive-strand RNA of about 9.6 Kb including 5′ untranslated region (5′-UTR), open reading frame (ORF) and 3′ untranslated region (3′-UTR). ORF is translated into a polypeptide chain which is subsequently processed into at least 10 different proteins including one nucleocapsid protein, two envelope proteins (E1 and E2) and non-structural proteins (NS2, NS3, NS4A, NS4B, NS5A and NS5B).
At present, there are about 17 anti-HCV compounds (such as ABT-450, BMS-650032, BI 201335, TMC-435, GS 9256, ACH-1625, MK-7009, etc) which have been into the stage of the pre-clinical and clinical development. All of them are designed to target HCV NS3/4A serine protease inhibitors. For example, the drug boceprevir developed by the pharmaceutical giant Merck (Merck) and the drug telaprevir developed by Vertex Pharmaceuticals, Inc. (Vertex), both are designed to target NS3/4A serine protease of HCV, which were approved by U.S. FDA in 2011. Showed clinically is that the cure rate of both drugs combined with standard treatment can be increased to approximately 75%.
Nevertheless, these drugs are just the beginning. Researchers are developing drugs targeting to more than one biological characteristic of hepatitis C virus. These drugs by combined administration are expected to solve the drug-resistant problem of HCV.